Electric hammer



May 4,1926. 1,583,5824

` IM, D. DOMINGUEZ ELECTRI C HAMMER Filed April 26, 1924 4 Sheets-Sheet 1 0f' 0, 90 gp attenta,

May 4, 1926. 1,583,582

M. D. DOMINGUEZ ELECTRIC HAMMER' Filed April 26, 1924 sheets-sheet 2 attoz m May 4 1926.

M. D. DOMINGUEZ ELECTRIC HAMMER 1924 4 Sheets-Sheet 3 Filed April 26 May. 4 1926. 1,583,582

v M. D. DOMlNGUEZ ELECTRI C HAMMER Filed April 2.6, 1924 Y 4 Sheets-Sheet 4 @ttor mm1 .3M AJM/A Patented May 4, 192,6. c

UNiTED STATES l11,583,582 PATENT oFFicE.

MANUEL D. DOMINGUEZ, OF NEW ORLEANS, LOUISIANA, ASSIGNOR OF ONE-HALF A'I0 cHAELEs A DENIS AND LOUISIANA oNE-EALF 'ro GEORGE SAEM?, Born or NEW oELEANs,

ELECTRIC HAMMER. i

Application mea april as, 1924. serial No. 709,260.

To all who-m it may conce-rn.'

Be it known that I,b MANUEL D. DOMIN- GUEZ, a citizen of Spain, and residentof New Orleans, in the parish of Orleans and State of Louisiana, have invented; certain new and useful Improvements in Electric Hammers, of which the following is a specification. My invention relates to a class of implements or appliances which may be conveniently described as electric chammers, in which a heavy body is rapidly reciprocated by electrical means, and which are' useful for hammering, riveting, chipping, caulking and analogous purposes.

The general object o-f the inventionlis to provide a tool or ap liance of this -class which is efficient, durahle, easily controlled, and is as simple in structure as the desired functions permit, and therefore can be manufacturedat moderate cost.

The invention, inv the preferred forms chosen for illustration, is embodied in a tool of moderate size which is therefore readily portable and well adapted for hand use; but many or all of the structural features are also applicable or adaptable with or without reasonable modifications to larger and heavier tools in the class Which may be conveniently described as non-portable, the principal distinction being that ,such tools usually require, because of their weight, some supporting or guiding means other than the hands of the operator.

Broadly described, the invention comprises a casing having at one end a handle and at the other end a mounting for a tool or working element, which may be readily interclianged for diferent classes of work. Within the casingis a reciprocable heavy piston or hammer suitably guided, and suitably disposed electro-magnetic means for impelling the hammer. Controlling mechanism, described for identification-as intermittent controlling mechanism or means, may be provided exterior to the casing and to a certain extent independent of the tool; but in the present embodiments of the invention this intermittent controlling means is enclosed in the casing, and is arranged to properly operate or vary the electro-magnetic circuits under the control of the moving hammer, to cause reciprocation thereof, whenever and so long as the main circuit is closed. There is also provided arbitrary or hand controlling mechanism, cwhich may be designated for identification as the main control device or mechanism, to close and. open the main circuit at thewill of the op` erator in orderfto make the automatic or intermittent controlling mechanism e'ective.

structions, as here shown, incorporated in the handle of the implement and is provided with a; trigger or linger piece projecting inwardly from the: handle.

The characteristics and advantagesof the l invention are further sufiiciently explained in connection with the following detail description of the accompanying drawings, which show certain exemplifying embodiments of the invention. After considering these embodiments, skilled persons will understand that many variations may be made within the principles of the invention, and I contemplate the employment of any structures that are properly within the scope of the appended claims.

Fig. 1 is a top plan view of a tool orap pliance embodying the invention in one form.

Fig. 2is a side relevation of the same.

Fig. 3 is a view partly in side elevation and partly in longitudinal section, with one 4of the cover plates removed.

Fig. 4 is a section at 4-4, Fig. 3.

Fig. 5 is a longitudinal section.

Fig. 6 is a detail view, partly in section, of one of the electro-magnets. i

Fig. 7 is a sectional detailview of one of the magnet core or vpole ieces showing the mode of attachment to t e main frame or casing.

Fig. 8 is a detail `view in side elevation of the intermittentv control mechanism or particularly the contact members thereof.

Fig. 9 is a view, partly in side elevation and partly in section, of the same.

Fig.' 10 is a plan view of the main control `or switch mechanism.

Fig. 10a is a side elevation of the same.

Fig. 10b is a transverse section.

iFigs. 11, 12 and 13 are diagrammatic views showingl dierent circuit arrangements, and with certain of the parts in positions especially chosen for explanatory purposes.

Fig. 14 is a view, mainly in longitudinal section, of a modified form of the appliance.

Fig. 15 is asection at 15j-15, Fig.14.y

'llhe electric hammer is built in, upon, or around a main frame or casing comprising sideA membersl, upper and lower end members-3 and'3,`and movable or removable side lates 89-90, which have beveled edges 90.- fitting in grooves or rabbets 90", so that the.

overlapping the end of sleeve 2, and is formed with an annular recess'lOO of subi stantial length,'in which -t the two legs oi a split pin 102. 'lhese legs also engage in holes in the sleeve. lin this way-the tool 98 is removably held in position and permitted to have the necessary reciprocatory movement, and such movement is definitely limited. To facilitate removal of the cotter or split pin 102, a longitudinal groove or notch 103 is formed in sleeve 2. Within the casing is the piston or hammer 16, usually formed of a suitable magnetic metal, such as steel .or preferably, for' magnetic reasons, of soft iron. lf necessary or desirable, the hammer may have hardened end pieces, which may or may not be detachable.' The hammer is provided with lugs 1,7, 17', 18, 18', each of which has a bushing 19, slidably fitting a guide rod 20.. Desirably there are two of these guide rods equally spaced and located near opposite sides of the casing. The lower endof each rod fits in a hole 21 in the lower end piece 3?, and isV secured by a pin 23. The upper end of each rod is formed with a portion 22 of reduced diameter tting in a socket inthe upper end piece 3. I r

The lower end ofthe hammer is arranged to strikethe inward end 101 of the tool 98. The upper end of the hammer is arranged to strike4 aplate or thick washer38, arranged for reciprocation in the lower portion of a .spring sleeve or casing 4 formed at the up per end of the main casing. A heavy spring 39 is located in this sleeve or housing and bears Jat one end against the housing end 6, and at the other end against the plate 38. This arrangementV takes up the shock of the Y hammer return stroke and also materially aids in speeding the hammer on its Working stroke in an obvious way.

A suitable plurality of electro-magnetic devices is located within the casing about the hammer. Specifically, in the present embodiment, there are three pairs of these devices, each of which is an electro-magnet comprising a core body 11 (Figs. 6 and 7) terminating in a pole piece or member 12, ,having a substantially partcylindrical contour to closelyit around a segment of the hammer withV suitable clearance. The core `members are secured against. suitable base plates 10 and held to the sideplates of the main casing or frame by screws 14. A suitable solenoid 13 is placed around. each core 11. 'lhethree pairs of electro-magnets are equally spaced throughout the length of the casing, onexpair being located near each end and the other at the middle, as clearly l"'13, the winding or wiring arrangement shown in Fig. 11 being preferred in some cases.l

For the automatic or intermittent control of the hammer, a slider, block or 'contact carrier 24, is mounted for. reciprocation on one of the guide rods 20. This contact carrier is located between two of the hamaner lugs, such as 17 and 18, and is actuated by them. The block properis of' metal 'or insulating material, and jmay consist of tw'o pieces 25, 25 and it is provided witha bushing 26 fitting around the guide rod. Contact lingers or blades 28, electrically connec-ted, project from opposite sides of the block 24. One of the contact blades moves between parallel fixed Contact blades or Lstrips 31, each of these being continuous,

and the other contact finger or blade 28, moves between the pairs of fixed contact strips 29, the confronting ends of the strips or blades of each pair being separated by a gap slightly shorter than the length of the moving contact 28, as clearly shown in Figs. 8 and 9. The tips of the -blades 29, and also the edges of the moving blade 28 which lco-operates with these spaced contact blades` may be provided with tips ksuch as 32 and 33 of hard metal which is resistant to the effects Vvof arcing, so that the blades or contacts proper may be of a suitable material, such as copper or brass. All of the fixed contact blades or strips are secured by brackets 34, 34 .to suitable supports, which may be certain of the magnetic pole pieces, suitable insulating bushings or other means being provided to insulate the contact blades or strips.

Arms or extensions 7 from the upper end of the spring housing 4 carry a casing or housing 9, which is the handle of the appliance and desirably has at least one removable cover plate' 94, secured by screws 95, 96, 97. The upper wall of the handle housing is formed with lugs or flangesr, 68, which co-operate with flanges 42, 42 formed on the ends of' an insulating block 41, Figs. 3, 10, 10L and 10". This block carries the main control or switch mechanism. A. conductor 43 secured to block 41 has a shown in Figs.3 and`5. Various suitable l ,to which one of the main internal leads or conductors 71 is secured. On the insulating block is alsosecured a conducting strip 48 of spring metal suitably bent to form a trigger arm and providedv with a flange 53 fitting in a slot in trigger piece 54 of metal or insulating material, which projects through a slot in the inward wall of the handle housingand is formed in arcuate shape to fit the finger of the operator. The contact blade 51 is secured to the trigger arm or may be integral with flange 53. At one end of the trigger arm or conductor strip 48 is a binding post 50 to which the other line wire 65 is connected. Secured also to the insulating block 41 are spring contact fingers 57 to co-operate with the blade 51. The contact fingers are in electrical connection with a' binding post 60 `to which the other internal main wire or conductor 72 is secured.

`When the trigger vpiece 54 is pressed inward, the main circuit is closed in an obvious way, and the circuit is broken by the .action of .the spring arm whenever the' trigger is released.S

The line conductors and 66 are arranged, in the form of an ordinary flexible double cable whichpasses through a rubber block G9 in an extension of the handlehousing, and this rubber block holds the cable with suiiicient firmness to prevent dislocation of the conductors from their binding posts. The cable is guarded against kinking or breaking by a helical wire 70, oneend of which is secured in the rubberblock.

The internal main wires 71 and 72 pass downward through a conduit formed in an extension 5 of one of the handle supports and spring housing 4 to a point where they enter the main casing. The internal main wires are then suitably branched and connected, as shown in the diagrams Figs. 11, 12 and 13. Specifically, wire 71 is branched to connect with all of the solenoids 18 toward one side of the casing, and each of these solenoids is cross-connected to the opposite one of its pair, the windings being suitably arranged to provide the proper polarities of the pole pieces 12, as indicated in the diagram. A conductor 81 goes from the left hand solenoid of the center pair, as viewed in Fig. 11, to one end of the continuous contact strips 30, and the other end of these strips is connected to the main internal wire 7 2. so that the. center pair of magnets is always energized. From the left hand solenoid of the lower pair of magnets, a conductor goes to the upper pair of spaced fixed contacts 29. The fixed and movable contacts are shown in these Idiagrammatic views in an arbitrary or false position, for the sake of illustrative clearness, although they could be so arranged in some practical embodiments of the invention. For the salme reason the hammer 16 is shown provided with an. upwardly extending stem 40, and the lugs 17 and 18, which are actually connectedto the hammer, are shown as connected to the stem in properly spaced relation to co-operate with the movable contact blades 28, which are shown in the diagrams as slidably mounted on the stern. From the left hand solenoid and the upper pairof magnets, a conductorv goes to the lower pair of spaced contacts 29.

Whenever the main circuit is closed, if the hammer is in an upper position, as shown in Fig. 11, the lower pair of magnets is energizedby contacts 28 closing the main circuit across theupper contacts 29 and contacts 30. The center magnets are always energized, and the hammer is pulled down by strong electromagnetic for-ce and `strikes a blow upon the inward end of the toolor working element 98'. Before the hammer reaches the end of its active stroke, lug 17 strikes the movable contacts 28 (or actually the contact block 24, Fig. 8) and moves the contacts downward. As one of the Contact members 28 bridges the gap between the upper and lower fixed contacts 29 all of the magnets are" energized for a brief instant, and thereafter the lower magnets are deenergized, and the upperu magnets are energized in an obvious fashion as the moving contacts 28 close the main circuits between the lower fixed contacts 29 and contacts 30. The hammer is then impelled upward in an obvious way; near the end of its upward or return stroke the circuits are again varied or reversed in an obvious fashion; the kinetic energy of the hammer is absorbed by the spring-controlled abutment plate 38; the recoil of the spring aids in speeding the hammer on its next active stroke; these operations are repeated indefinitely as long as the main circuit' is closed.

Fig. 12 shows a different method of winding the solenoids and connecting them, which is preferred in some cases.

Fig. 13 shows that the hammer may 'in some cases be guided in a sleeve or cylinder 16', which may or may not be of insulating material, located between the magnet pole faces.

Figs. 14 and 15 show a modified struc-l ture or arrangement in which the main hous- I l spool rests against flange 150, and the lower spool is engaged by a plate 83which fits within the lower end of the casing and has about its central aperture, a socket'84 in which rest-s the lower end of sleeve 148.` rlhe lower end of the casing is closeda by a cap 115, which has at its outer' periphery a screw thread flange l116 in engagement with the screw thread end of the casing, and at its center the cap is formed with a sleeve 117 projecting within the sleeve 148. A compressible gasket 118 of rubber or other suitable material is placed between the cap and plate 83 adjacent the periphery of the latter forthe double purpose of retaining in position the described parts, namely the;

sleeves 148 and 55, magnet spools or solenoids 153 and 154, and the plate 83, and to form a moisture-proof seal at the lower end of the casing. An extension 119 is centrally.

formed on cap 115 to receive and retain a suitable tool, such as 184, substantially in the same manner in which the total or working member 98 is held insleeve 2 in previously described constructions. lln the present instances the working implement 184 is a chipping or caulking tool.

rlhe piston or hammer 43 is located with a sliding lit in sleeve 148. rlhe sleeve has at its upper end a head 149 and a spring 52 is located between this head and the upper end of the hammer, with a washer 51 interposed between the spring and the hammer when necessary or desirable. Since the hammer moves'in what is practically a closed cylinder, longitudinal channels144 are provided in the periphery of the hammer to permit air to pass from one end of this cylinder to the other, and so to avoid any pneumatic impedance of the hammer movement. A stem 40 extends upward from the hammer through an aperture in sleeve head 149, this stem corresponding substantially to the arrangement described in connection with diagrammatic Figs. 11 to 13. On an upper part of the stem, within the chamber formed .by casing extension 77, are spaced discs, or flanges 17 and 18, and a contact member 165 of insulating material or else suitably in- -sulated :from the stem, is arranged to slide between the flanges.

Spring contact blades or lingers 162 elec- 4trically connected, extend from the contact insulated from it'by strlps of suitable insulatinff material' are channel Contact strips 156, 157` and v158, of which the strip 156, 10-

cated on one. side of the sleeve is continuous, and the other strips 157 and 158 located in line with each other at the other side of the sleeve arediscontinuous and their adjacent ends are separated by insulating 'material 159, which may be a p-art of the insulating strip on which the contact members rest.

(lne of the mainrinternal conductors 166 leading from the switch mechanism con-v` trollcdby trigger 54 is connected to a binding post 167 at the upper end of contact strip 156. The other main internal conductor 172 is suitably branched and connected to ends of the solenoid windings. The other end of one of the solenoids is connected to -a binding post 161 which is in electrical connection with cont-act stri 158, and the other end of the other solenord windinr is connected by a conductor 168 to a binding post 169, which is in electrical connection with contact strip 157. 1

Whenever the main circuit is closed, if the hammer is in an upper position, as shown in Fig. 14, the lower solenoid 154 is energized and the hammer is drawn smartly downward and strikes a blow on the inward end ofrthe tool. Somewhat before the hammer strikes ange 17, stem 40 strikes contact carrier 165 and moves it downward so that the circuit including contact strip 157, is

broken and the circuit is established betweenstrip 156 and strip 158, and thereupon the the hammer. Near the yupper end of the hammer movement the circuit is avain reversed in an obvious Way and the alnmer momentum is yieldably absorbed by spring 52, and the reextension of the spring aids in speeding the hammer on its next downward stroke; these operations are repeated indefinitely.

Provision may be made for lubrication at important points. For instance, the slider or contact carrier 24, Fig. 3, may have an oil hole 27 and oil holes a, may be provided in lugs 17 17', 18 and 18', Fig. 5.

Provision is also made for insulating parts where necessary or desirable by means of strips of insulation and insulating bushings, some of which are referred to and others are not mentioned, since they may be provided as usual in electrical constructions or arrangements.

`What I claim is 1. An appliance of the-class described, comprising aicasing, a plurality of electromagnets disposed longitudinally therein,

longitudinal guide ro'ds adjacent opposite casing walls and detachably secured in the casing, a hammer arranged to reciprocate in the casing, and lugs thereon having sliding engagement with the guide rods.

2. An appliance of the class described, comprising a casing, a'plurality of electromagnets vdisposed longitudinally therein,

longitudinal guide vrods adjacent opposite casing walls and detachably secured in the casing, a hammer arranged to reciprocate in the casing, lugs thereon having sliding engagement with the guide rods, a contact carrier mounted for reciprocation on one of the guide rods between two of the hammer lugs, contacts on the carrier, and Xed contacts cooperating therewith.

3. An appliance of the class described, comprising a casing, a plurality of electromagnets disposed longitudinally therein, longitudinal guide rods adjacent opposite casing walls and ldetachalcly secured in the casing, a hammer arranged to reciprocate in the casing, lugs thereon having Sliding engagement with the g'uide rods, a Contact carrier mounted for reciprocation on one of the guide rods between two of the hammer lugs with provision for lost motion, contacts on the carrier, and fixed contacts cooperating therewith.

Signed at New Orleans, in the parish of,` Orleans and State of Louisiana this 19th day of April A. D. 1924.

- MANUEL D. DOMINGUEZ. 

